High-dose intravenous pulse methylprednisolone is an important therapeutic modality for many autoimmune conditions in both children and adults. Adverse effects of this therapy include hypertension, hyperglycemia, and, in children, behavioral changes. Cardiac rhythm disturbances, both tachyarrhythmias and bradyarrhythmias, have been reported in adults but much less commonly in children. Here we report our experience over a 6-month period with 5 children with rheumatic diseases who developed sinus bradycardia during consecutive daily therapy with intravenous pulse methylprednisolone. Reductions in resting heart rate of between 35% and 50% of baseline were observed in each case. All patients were asymptomatic, and all recovered spontaneously over a variable period of time after cessation of pulse therapy. Sinus bradycardia after repeated administration of high-dose pulse methylprednisolone in children may be more common than previously appreciated.